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The McCain/Clinton Surreal View of Global Warming
Volume 8, Number 34: 24 August 2005

U.S. Senators John McCain and Hillary Clinton, together with Senators Susan Collins and Lindsey Graham, recently completed a tour of parts of Alaska and Canada "to see firsthand the effects of global warming," which is how one reporter described the purpose of their highly-publicized junket. So what did they discover that led McCain to state, as reported by Associated Press Writer Dan Joling, that the trip was "valuable for the accumulation of evidence," specifically, evidence that could be used to support the McCain-Liebermann bill that would limit anthropogenic greenhouse gas emissions?

Among the items cited by Joling were "anecdotes from Alaskans and residents of the Yukon." As elucidated by Senator Graham, according to Joling, "if you can go to the native people and listen to their stories and walk away with any doubt that something's going on, I just think you're not listening," or as McCain is reported to have said, "anyone doubting the effects of human activity on global climate change should talk to the people it affects in Alaska and the Yukon."

Well, of course, "something's going on," but the important questions are What? and Why? McCain and Clinton say that the what is unprecedented global warming and that the why is because of anthropogenic CO2 emissions from the burning of fossil fuels. To our way of thinking, however, real-world data far outrank anecdotes and stories when it comes to answering these key questions; and when the former are employed, some vastly different answers are obtained.

To focus our efforts in illustrating this fact, we concentrate on what it was that enticed McCain and company to visit Alaska and the Yukon in the first place. According to another report of the trip, McCain claims that the planet's north and south polar regions "are the miner's canaries on the issue, showing the effects of global warming first." Hence, it was only to be expected that local residents of the planet's north polar region would regale him and his associates with tales of dwindling sea ice, coastal erosion, melting permafrost and the northward spread of spruce beetles. And it was those anecdotes and stories, according to one press report, that "confirmed his belief that humans are contributing to global warming."

But what does science have to say about the issue? This is a question we have broached repeatedly on our website, focusing on the "canary in the coal mine" claim as applied to earth's polar regions in three consecutive editorials, those of 10 Mar 2004, 17 Mar 2004 and 24 Mar 2004.

In the first editorial, we describe the study of Overpeck et al. (1997), who combined paleoclimatic records from lake and marine sediments, trees and glaciers to develop a 400-year history of circum-Arctic surface air temperature. From this record they determined that the most dramatic warming of the last four centuries (1.5C) occurred between 1840 and 1955, over which period the air's CO2 concentration rose by 28 ppm. Then, from 1955 to the end of the record (about 1990), the mean circum-Arctic air temperature actually declined by 0.4C, while the air's CO2 concentration rose by 41 ppm. On the basis of these observations, we calculate that over the first 115 years of warming, when the air's CO2 concentration rose by an average of 0.24 ppm/year, air temperature rose by an average of 0.013C/year; while over the final 35 years of the record, when the air's CO2 content rose at a mean rate of 1.17 ppm/year (nearly five times the rate at which it had risen in the prior period), air temperature actually decreased, at a mean rate of change (0.011C/year) that was nearly the same as the rate at which it had previously risen. Hence, it is abundantly clear from this analysis of air temperature behavior in the Arctic (where CO2 effects are supposed to be most evident and first detectable) that whatever effect the increase in the air's CO2 content might have had on earth's surface air temperature over the period of study was totally overpowered by the simultaneous effect of whatever changes may have occurred in whatever is the chief determinant of climate change on earth.

In the second editorial, we concentrate on directly-measured temperatures, as opposed to the reconstructed temperatures used by Overpeck et al., focusing on the study of Polyakov et al. (2003), who derived a surface air temperature history that stretches from 1875 to 2000 based on measurements made at 75 land stations and a number of drifting buoys located poleward of 62N latitude. From 1875 to about 1917, the surface air temperature of this huge northern region rose hardly at all; but then it took off like a rocket, climbing 1.7C in just 20 years to reach a peak in 1937 that has yet to be eclipsed. During this 20-year period of rapidly rising air temperature, the atmosphere's CO2 concentration rose by a mere 8 ppm. But then, over the next six decades, when the air's CO2 concentration rose by approximately 55 ppm or nearly seven times more than it did throughout the 20-year period of dramatic warming that had preceded it, the air temperature of the region poleward of 62N latitude experienced no net warming and, in fact, may have actually cooled a bit.

In light of these results, as before, it is difficult to claim much about the strength of the warming power of the 75-ppm increase in the air's CO2 concentration that occurred from 1875 to 2000, other than to say it was miniscule compared to whatever other forcing factor or combination of forcing factors was concurrently having its way with the climate of the Arctic. One cannot, for example, claim that any of the 1917 to 1937 warming was due to the 8-ppm increase in CO2 that accompanied it, even if augmented by the 12-ppm increase that occurred between 1875 and 1917; for the subsequent and much larger 55-ppm increase in CO2 led to no net warming over the remainder of the record, which suggests that just a partial relaxation of the forces that totally overwhelmed the warming influence of the CO2 increase experienced between 1937 and 2000 would have been sufficient to account for the temperature increase that occurred between 1917 and 1937. Understood in this light, CO2 does not even enter the picture.

In the third of our "canary in the coal mine" editorials, we concentrate on perhaps the most climatologically-significant area of the Arctic, i.e., Greenland, where the complete melting of its ice sheet could raise sea levels globally by some five to six meters. In this endeavor, we focus on the work of Chylek et al. (2004), who analyzed the temperature histories of three coastal stations in southern and central Greenland that possess almost uninterrupted temperature records stretching from 1950 to 2000. They discovered that "summer temperatures, which are most relevant to Greenland ice sheet melting rates, do not show any persistent increase during the last fifty years." In fact, working with the two stations with the longest records (both over a century in length), they determined that coastal Greenland's peak temperatures occurred between 1930 and 1940, and that the subsequent decrease in temperature was so substantial and sustained that current coastal temperatures "are about 1C below their 1940 values." Furthermore, they note that "at the summit of the Greenland ice sheet the summer average temperature has decreased at the rate of 2.2C per decade since the beginning of the measurements in 1987." Hence, as with the Arctic as a whole, Greenland did not experience any net warming over the most dramatic period of atmospheric CO2 increase on record. In fact, it actually cooled during this period ... and cooled significantly.

At the start of the 20th century, however, Greenland was warming, as it emerged, along with the rest of the world, from the depths of the Little Ice Age. What is more, between 1920 and 1930, when the atmosphere's CO2 concentration rose by a mere 3 to 4 ppm, there was a phenomenal warming at all five coastal locations for which contemporary temperature records are available. In fact, in the words of Chylek et al., "average annual temperature rose between 2 and 4C [and by as much as 6C in the winter] in less than ten years." And this warming, as they note, "is also seen in the 18O/16O record of the Summit ice core (Steig et al., 1994; Stuiver et al., 1995; White et al., 1997)." With respect to this dramatic temperature rise, which they call the great Greenland warming of the 1920s, Chylek et al. correctly conclude that "since there was no significant increase in the atmospheric greenhouse gas concentration during that time, the Greenland warming of the 1920s demonstrates that a large and rapid temperature increase can occur over Greenland, and perhaps in other regions of the Arctic, due to internal climate variability such as the NAM/NAO [Northern Annular Mode/North Atlantic Oscillation], without a significant anthropogenic influence." Yet again, therefore, we have another situation where something other than the air's CO2 concentration rode roughshod over whatever tiny effect the historical increase in the innocuous trace gas' concentration may have had on earth's surface air temperature.

For information on an even greater body of relevant scientific evidence that pertains specifically to Alaska, we direct your attention to our Subject Index Summary Temperature (Trends - Regional: North America, Alaska), where we review the results of several additional studies dealing with proxy temperature reconstructions, as well as a couple that focus on permafrost, all of which come to pretty much the same conclusion as that reached in the editorials discussed above, i.e., that there is absolutely no real-world data that suggest that the historical increase in the air's CO2 concentration has had any effect whatsoever on the climate of Alaska.

Interestingly, these observations lead us to actually agree with some of Senator Clinton's statements on the subject, such as "I don't think there is any doubt left for anyone who actually looks at the science," which she was quoted by Joling as saying, as well as "the science is overwhelming." Unfortunately, what she and Senator McCain call science is something radically different from what we call science. Also, we find we agree with Clinton when she says that some people "just keep saying something no matter how untrue and unfactual it might be, over and over and over again, and try to drive the politics to meet [their] ideological or commercial agenda." However, we feel that this astute observation better fits her and Senator McCain than the people to whom she directs it. Surely you must too, if you put more credence in real-world data than in anecdotes and stories.

Sherwood, Keith and Craig Idso

References
Chylek, P., Box, J.E. and Lesins, G. 2004. Global warming and the Greenland ice sheet. Climatic Change 63: 201-221.

Overpeck, J., Hughen, K., Hardy, D., Bradley, R., Case, R., Douglas, M., Finney, B., Gajewski, K., Jacoby, G., Jennings, A., Lamoureux, S., Lasca, A., MacDonald, G., Moore, J., Retelle, M., Smith, S., Wolfe, A. and Zielinski, G. 1997. Arctic environmental change of the last four centuries. Science 278: 1251-1256.

Polyakov, I.V., Bekryaev, R.V., Alekseev, G.V., Bhatt, U.S., Colony, R.L., Johnson, M.A., Maskshtas, A.P. and Walsh, D. 2003. Variability and trends of air temperature and pressure in the maritime Arctic, 1875-2000. Journal of Climate 16: 2067-2077.

Steig, E.J., Grootes, P.M. and Stuiver, M. 1994. Seasonal precipitation timing and ice core records. Science 266: 1885-1886.

Stuiver, M., Grootes, P.M. and Braziunas, T.F. 1995. The GISP2 18O climate record of the past 16,500 years and the role of the sun, ocean and volcanoes. Quaternary Research 44: 341-354.

White, J.W.C., Barlow, L.K., Fisher, D., Grootes, P.M., Jouzel, J., Johnsen, S.J., Stuiver, M. and Clausen, H.B. 1997. The climate signal in the stable isotopes of snow from Summit, Greenland: Results of comparisons with modern climate observations. Journal of Geophysical Research 102: 26,425-26,439.